PROJECT SUMMARY Disparities in cardiovascular (CV) diseases by socioeconomic status (SES) and race/ethnicity are pronounced in our society, and the processes that lead to these disparities begin in childhood. Previous intervention efforts have targeted individual lifestyle changes in health behaviors, but with limited success in low SES, minority youth. We propose a novel intervention to reduce CV risk in low SES, minority children (under 21 by NIH guidelines) that focuses on social relationships ? specifically mentoring ? as a way to create bi-directional benefits for CV health in youth. The rationale for this intervention is based both on work showing that receiving social support has benefits for physical health, and on work demonstrating that helping others is associated with better physical health. In this proposed intervention study, college students will serve as mentors to elementary school students (8th graders). 250 college students and 250 Chicago Public School 8th graders will be randomized to either serve as a mentor/mentee or to be in a control group. Students will participate in a weekly mentoring intervention throughout one school year. Assessments will occur at 3 time points during the school year. All mentors and mentees will come from low-income families and underrepresented minority groups, thus allowing us to focus on improving CV health in an at-risk population that experiences a disproportionate share of the CV burden in the U.S. The first aim of the project is to investigate whether mentors can reduce CV risk (obesity; blood pressure; cholesterol; blood glucose) in low-income, minority youth mentees relative to a control group of 8th graders. The second aim is to investigate whether serving as a mentor can reduce CV risk in the college student mentors compared to a control group of college students. The third aim is to understand how mentoring influences the intervention targets of psychosocial, health behavior, and biological variables, and whether these variables mediate the impact of mentoring on CV health. Drawing from the stress buffering model of social support, we propose that mentoring fosters the development of strong social relationships that can scaffold behavioral changes and hence mitigate the effects that stress has on inflammation and CV health via 2 pathways: psychophysiological and health behaviors. In the psychophysiological pathway, mentoring creates more adaptive cognitive, emotional, and behavioral responses to life stressors, which in turn mitigate responses of the sympathetic and neuroendocrine systems to stress. Over time, this reduces inflammation and improves CV health. In the health behaviors pathway, the scaffolding from mentoring relationships mitigates the associations of stress with detrimental health behaviors that in turn are linked to both inflammation and CV health. Through this study, we take a social relationships- oriented primary prevention approach to reducing health disparities by targeting CV risk factors that emerge early in life and that predict clinical CV disease outcomes into adulthood and by focusing on low-income, minority mentors and mentees who represent an at-risk, underserved, and disadvantaged group of youth.